Electrical converter

Abstract

An electrical converter chosen from the group consisting of an inverter able to generate an AC voltage from a DC voltage and a rectifier able to generate a DC voltage from an AC voltage. This converter comprises a first inductor and a controllable switch that are connected in series between first and second DC voltage ports. The converter comprises a piezoelectric resonator comprising: a first electrode connected directly to a first power terminal of the switch, a second electrode connected directly to a second power terminal of the switch, and a piezoelectric material interposed between the first and second electrodes.

The invention claimed is: 
     
       1. An electrical converter chosen from the group consisting of an inverter configured to generate an AC voltage from a DC voltage and a non-reversible rectifier able to generate a DC voltage from an AC voltage, the converter comprising:
 a first and a second DC voltage port via which the DC voltage is received or delivered, 
 a first and a second AC voltage port via which the AC voltage is received or delivered, 
 a first inductor and a controllable switch that are connected in series between the first and second DC voltage ports, the controllable switch comprising a first and a second power terminal and a control terminal, the controllable switch being connected to the first inductor via the first power terminal, the switch configured, in response to a control signal received on the control terminal, to switch at a frequency greater than 1 MHz, between:
 a closed state in which the first and the second terminals are electrically connected to one another, and 
 an open state in which the first and second power terminals are electrically isolated from one another, 
 
 a second inductor configured to pass through a current modulated by the controllable switch, the second inductor and the switch being connected in series between the first and second AC voltage ports, 
 wherein the converter comprises a piezoelectric resonator comprising:
 a first electrode connected directly to the first power terminal of the switch, 
 a second electrode connected directly to the second power terminal of the switch, an 
 a piezoelectric material interposed between the first and second electrodes. 
 
 
     
     
       2. The converter as claimed in  claim 1 , wherein:
 the converter comprises a circuit for driving the switch that connected to the control terminal of the switch, the drive circuit being configured to periodically switch the switch between the open state and the closed state, a switching frequency of the switch is equal to a frequency f s , and 
 the piezoelectric resonator has a resonant frequency between 1.5 f s  and 2.5 f s . 
 
     
     
       3. The converter as claimed in  claim 2 , wherein the frequency f s  is between 10 MHz and 300 MHz. 
     
     
       4. The converter as claimed in  claim 1 , wherein a quality factor of the piezoelectric resonator is greater than or equal to fifty or one hundred. 
     
     
       5. The converter as claimed in  claim 1 , wherein various components of the converter are dimensioned such that, each time the switch switches, a voltage between the first and second power terminals is less than 2 V. 
     
     
       6. The converter as claimed in  claim 1 , wherein the converter comprises a single controllable switch. 
     
     
       7. The converter as claimed in  claim 1 , wherein the first inductor value is between 0.3 Lf ini  and 3 Lf ini , where Lf ini  is equal to 1/(9π 2 f s C 0 ), where:
 f s  is the switching frequency of the controllable switch, and 
 C o  is a series capacitance of the piezoelectric resonator. 
 
     
     
       8. The converter as claimed in  claim 1 , wherein a value of the second inductor is between 0.3 Ls ini  and 3 Ls ini n where Ls ini  is equal to X s /(2πf s ) and
 a reactance X s  is equal to Rc((4 V in /π√2) 2 /(P out Rc)−1) 0.5 , where 
 f s  is the switching frequency of the controllable switch, 
 V in  is a DC voltage between the first and second DC voltage ports when the converter is used as the inverter, 
 Rc is an electrical resistance of a load connected between the AC voltage ports when the converter is used as the inverter, and 
 P out  is power delivered to the terminals of the load connected between the AC voltage ports. 
 
     
     
       9. The converter as claimed in  claim 1 , wherein the converter comprises a capacitor connected directly in parallel to the first and second power terminals of the switch. 
     
     
       10. The converter as claimed in  claim 1 , wherein the converter is the inverter. 
     
     
       11. The converter as claimed in  claim 2 , wherein the frequency fs is between 1 MHz and 300 MHz.